There are many different types and styles of tape cassettes currently available for use with tape player/recorders. The available cassettes generally include a cassette housing made of two sections which fit together to define an open space therebetween. A pair of tape reels, on which a magnetic tape is mounted, is mounted in the open space so that the reels can rotate to thereby guide the tape across the surface of the magnetic head.
The quality of the sound being recorded or reproduced is enhanced when the tape runs exactly perpendicularly across the magnetic head. Any deviation from perpendicularity results in degradation of sound quality. It is therefore important that while a tape cassette is produced as economically as possible, it still provides for the appropriate perpendicularity between the tape and the magnetic head.
One relatively inexpensive method used to produce the components of a tape cassette is by injection molding plastic materials into the appropriate shapes. For example, U.S. Pat. No. 4,506,846 to Gelardi et al discloses a tape cassette which includes upper and lower halves which are mounted together with a molded plastic tape guide mounted in the space between the cassette halves. As is the case with other cassettes, the cassette provided by Gelardi et al includes two reels and a length of magnetic tape on the reels. The tape guide includes two metal pins spaced apart from each other over which the tape slides as it passes across the magnetic head of the tape player/recorder. The metal pins are provided to maintain the perpendicularity of the tape to enhance the sound performance of the cassette. Gelardi et al disclose that the pins are provided so that the "desired perpendicularity is no longer made dependent on the current state of the molding art to create the mold for forming the tape guide."
Gelardi et al disclose that the metal pins are required to overcome various problems they found with the cassette described in U.S. Pat. No. 3,934,842 to Posso. The '842 patent to Posso discloses a cassette for recording tape which includes a body, a cover, and a tape guide all molded independently of plastic. The tape guide is in one piece and includes two transverse ribs, each of which includes a central notch with a rounded edge. The rounded edges are coplanar and define a sliding surface for the tape.
Two pins, separate from the guide, are on the base of the cassette body adjacent the ends of the guide. It is disclosed that the rounded edge sliding surface is parallel to the geometric axis of rotation of the reels and to the face of the recording and reading head.
Since the pins on which the rollers are mounted are not on the tape guide, but, instead, are on the body of the cassette, which is a molded part separate from the guide, the alignment of the pins relative to the various surfaces of the tape guide may not be as desired.
There is a need in the art for a tape cassette which: (1) does not require metal pins, as are required by the cassette disclosed by Gelardi et al; (2) is of a simple design; (3) is economical to manufacture; and (4) ensures the perpendicularity of the tape relative to the magnetic head to thereby optimize sound reproduction and recording.